Detachable synthetic rope connector

ABSTRACT

A detachable synthetic rope connector with connector body, bale, main load pin sub assembly, and a restraining load sub assembly that permits the use of large diameter synthetic and other mooring components such as cable and chain on offshore work vessels without specialized deck equipment. The inventive connector allows for safe and redundant restraint of a mooring segment in order to provide transfer of the tension load while providing connection features that simplify separation and the reduction of safety risks to vessel working personnel and the environment, and the features allow for the connector to be separated easily while the portion holding the rope is restrained while the bale can be removed.

This application claims priority from U.S. Provisional application Ser.No. 61/215,418 (the ‘418 application’) filed May 5, 2009. The '418application is incorporated here by reference.

BACKGROUND OF THE INVENTION

Offshore deepwater mooring systems frequently employ mooring segmentsthat are synthetic. The synthetic mooring segments have lengthlimitations requiring that multiple segments be used in deep locations.Processes of installation, moving, inspection and modifications to themooring systems require that the segments be lifted onto an offshorework vessel and be restrained to perform the required operations.

The lifting of mooring segments along with supporting anchors and seabedchain lengths above the seabed, develop significant tension due to thegravity loads. These tension levels can exceed 20 tons.

Mooring segments must be separated when a winch drum or storage reel isfull or when it is necessary to change or replace a connector in themooring segment. Prior to separating the mooring segment, it is furthernecessary to release the tension on the connection to be separated byrestraining the subsea side of the mooring segment and transferring thetension from the segment to be separated.

When large diameter synthetic mooring lines are being used, the workvessels may not have sufficiently large deck equipment to restrain thesystem and allow the connection to be separated. The existing deckmounted restraint equipment is generally not large enough for the largersynthetic ropes proposed for use by the industry.

SUMMARY OF THE INVENTION

The unique features of the inventive detachable synthetic rope connectorallow commonly available shackles and cables to be used with pad-eyesmounted on the deck of a work vessel to handle large synthetic and othermooring components that exceed the capacity of the installed vessel deckrestraint equipment. These features also increase the safety of theoffshore work by providing redundancy when servicing the mooringsystems. The use, function and configuration of these features for themooring connector are embodied by the present invention.

The present invention comprises an optimized bale that is detachablefrom a connector body. The disconnection of the bale from the connectorbody allows a single connector to be separated while restraining ropeunder tension. The bale cross section is optimized in a manner whereinthe cross section of the apex differs from the cross section of thebottom portions. Further the geometric centerline of the bale differsfrom a pure radius to allow optimization of the shear, bending andtension components of the stresses induced by the loading at the apex.The variation of the cross section is such that each portion isoptimized for stress while minimizing weight and further allowing thepassage of the bale through intended existing connecting links and chainends. The optimization is performed to require the unique feature, incertain limits of load rating, the rotation of the bale through anintended connecting link as a means of further minimizing weight andstress for increased safety.

Other features that are desirable and embodied in the invention is theability to reel the connector directly onto a storage reel withoutdamaging synthetic rope. These features include external radii on allsurfaces that are sufficiently large to prevent high local contact loadson the synthetic or other rope compositions. These radii are at least ½inch in radius but may be as large as 6 inches to prevent excessivecontact forces and damaging contact stresses on contacted rope onstorage reels.

While the use of this invention is particularly useful for largediameter synthetic rope connectors it is equally beneficial for wirerope and chain installations.

It is an object of this invention to provide a detachable connector forrope, having a connector body with a left side and a right sideconfigured to receive a rope wrapped around said connector body, anoptimized bale with an apex, a right side and a left side and a bottomright side end and a bottom left side end mounted on and detachable fromsaid connector body, a main load pin subassembly extending from theright side to the left side of both the connector body and bale, and arestraining load subassembly extending from the right side to the leftside of the connector body.

It is a further object that the connector body comprises a cavityextending from the right side to the left side of the connector body toreceive the main load pin subassembly, a hole extending from the rightside to the left side of the connector body to receive the restrainingload subassembly, and a recess on the right and left side of theconnector body to respectively receive and constrain the bottom rightside end and bottom left side end of the bale, and the bale furthercomprises a hole extending from the right side to the left side toreceive the main load pin subassembly, said hole having a recess at theright side and left side.

It is a further object that the main load pin subassembly has a mainload pin with a right end and a left end, each of the ends havingthreaded holes, a shoulder on one of the ends configured to seat in theright or left side recess of the bale, a circular end plate on the otherof the ends, configured to seat in one of the recesses of the bale andbeing fixed to the pin with fasteners, and the restraining load subassembly has a main restraining pin having a right end and a left end,each of the ends fitted with padeye caps and retaining pins. Alternativeto a shoulder on one end, both ends of the pin may be configured toaccept circular plates each being fixed to the pin with fasteners. Theradius of said fasteners being such that the plates are fixed to the pinand not to the connector body preventing torque due to relative motionof the pin with the connector body from generating high torsional loadson fasteners removing danger of loosening an end plate on the pin.

It is a further object of this invention to provide a method ofdisconnecting a rope connection under tension comprising the steps of :providing a connector for rope, comprising: a connector body with a leftside and a right side configured to receive a rope wrapped around saidconnector body, a bale with a right side and a left side and a bottomright side end and a bottom left side end mounted on and detachable fromsaid connector body, a main load pin subassembly extending from theright side to the left side of both the connector body and bale, and arestraining load subassembly extending from the right side to the leftside of the connector body; engaging the restraining load subassemblyand relieving tension from the bale when restrained thereby allowingremoval of the main load pin subassembly and detachment of the bale fromthe connector body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts the inventive detachable synthetic rope connector in anisometric view without the rope being shown and without any attachmentsto the bale. The major components that extend outside the connector bodycan be seen in this view.

FIG. 1A depicts a preferred embodiment of the inventive detachablesynthetic rope connector in an isometric view without the rope beingshown and without any attachments to the bale. The major components thatextend outside the connector body can be seen in this view

FIG. 2 depicts the inventive detachable synthetic rope connector in aside view.

FIG. 2A depicts a preferred embodiment of the inventive detachablesynthetic rope connector in a side view.

FIG. 3 depicts the connector body in an isometric view.

FIG. 3A depicts a preferred embodiment of the connector body in anisometric view.

FIG. 4 depicts the main load pin sub assembly in an isometric view.

FIG. 4A depicts a cross section of one end of the main load pinsubassembly.

FIG. 5 depicts the restraining load sub assembly in an isometric view.

FIG. 6 depicts the bale in an isometric view.

FIG. 6A depicts a preferred embodiment of the bale in an isometric view.

DETAIL DESCRIPTION OF THE INVENTION

FIG. 1 presents the invention, termed a detachable rope connector 1,consisting of an assembly that includes a connector body 10 with a leftside 101 and a right side 102, a bale 20 with an apex 201, a right side202, a left side 203, a bottom right side end 204 and a bottom left sideend 205, a main load pin sub assembly 30 and a restraining load subassembly 40. FIG. 1A depicts a preferred embodiment of the inventivedetachable rope connector.

The connector body 10 shown in FIGS. 3 and 3A and separate from theassembly in FIGS. 1, 1A, 2 and 2A, is formed similar to that of aconventional rope thimble from the standpoint that a synthetic rope 50or rope of other construction, indicated in phantom lines in FIG. 2, canbe wrapped around the connector body 10 and secured and therebytransfers a tension load from the rope 50 to the structure of theconnector body 10.

As illustrated by the components shown in FIGS. 1, 1A, 2 and 2A, thedetachable rope connector 1 transfers loads from the rope 50 through theconnector body 10 via the main load pin sub assembly 30 to the bale 20and consequently to other connectors or chain elements. The bale 20 isremovable when the connector body 10 is restrained and the tension cantherefore be relieved.

In FIGS. 3, and 3A, the connector body 10 is shown to include a cavity11 through which the main load pin sub assembly 30 extends. Theconnector body 10 also includes a second means of connection to theconnector body illustrated by a hole 12 by which the restraining loadsub assembly 40 connects. The second means to restrain the connectorbody 10 is shown utilizing a restraining pin 41 with padeye caps 45secured by pins 47. It is apparent that slotted means of variousdescriptions can be made in the side or other areas of connector body 10that can be used to restrain the connector body 10 from moving to allowthe bale 20 to be removed even while the rope 50 is under tension.

FIG. 4 depicts the main load pin sub assembly 30 with a main load pin 31with a right end 311 and a left end 312 and a circular nut plate 35 onone of the ends 311 or 312. The main load pin assembly 30 is configuredto present a surface free of sharp edges to prevent damage to syntheticrope and to prevent snags. The main load pin 31 is provided withthreaded holes 32 at both ends on its centerline 33 to provide for useof screw eyes and other fittings that connect into the threaded holes 32to lift and assist the positioning and removal of the main load pin 31from the connector body 10 and bale 20 when connected. The main load pin31 is configured with a shoulder 37 on the end opposite the circular nutplate 35 that seats within a recess 21 of the bale 20 as shown in FIG.6. A threaded end 34 is provided opposite the shoulder 37 on the mainload pin 31 to which the circular nut plate 35 is attached.

The circular nut plate 35 of the main load pin sub assembly 30, shown inFIG. 4, also seats within a recess 22 of the bale 20. The circular nutplate 35 includes spanner holes 36 that extend through its thickness.The radii of the spanner holes 36 are less than the radius of the bodyof the main load pin 31. This feature allows the spanner holes to beused to lock the circular nut plate 35 to the main load pin 31 bydrilling and tapping at final assembly. By restraining the circular nutplate 35 directly to the main load pin 31, the circular nut plate 35 isprevented from loosening although the main load pin 31 may be allowed torotate.

In FIG. 4A, a cross section of one end of the main load pin subassembly30 is shown with a circular nut plate 35 locked on the end of the mainload pin 31 through spanner holes 36, and a threaded hole 32 on thecenterline 33 of the main load pin 31 and accessible through thecircular nut plate 35.

FIG. 5 depicts the restraining load sub assembly 40 with a main pin 41,with a right end 411 and a left end 412, padeye caps 45 and retainerpins 47. The provision for end mounted connections such as the padeyecaps 45 or similar appurtenances to which external cable or othersystems can be attached provides restraint for the rope 50 by means ofthe connector body 10 allowing tension to be transferred from the bale20 allowing separations and connections to be under slack conditions.

FIG. 6 depicts the bale 20 that is configured to pass through chain whendisconnected from the connector body 10. The bale 20 is also configuredto connect two bales together where intended or to utilize a master linkor similar connecting link for attachments. To prevent unwanted rotationof the bale 20 and the connector body 10, a recess 13 in the connectorbody 10 is provided to constrain the bale 20. The cross section of thebale is configured to reduce stress intensification factors and toreduce contact stresses when interconnecting two bales or a bale 20 tochain or chain fittings by approximating the required radius of theintended mating components. The bale is further recessed into theconnector body. The recess allows for pre-describing the allowablerotational deflection to the degree desired for the application withoutattempting to utilize keys or cross pins that would be subjected to highshear loading. The recess of the bale further limits the inner gapdistance in the bale which reduces the combined stresses in the baleallowing for a reduced cross section that may therefore pass throughchain and smaller diameter access holes in existing connecting links.The cross section of the bale is further configured to minimize stressesand weight yet allow connection through smaller connecting link accessholes. The cross section of the bale is optimized to the degree that insome instances may require up to 90 degrees rotation during insertioninto the mating connecting link. These features are unique and veryuseful and together reduce handling weight and increase safety in theworkplace.

The present invention provides features which allow one end of theconnector, the bale 20 or other components to which the tension has beenrelieved, to be removed while restraining the connector body 10 to whichthe rope 50 is attached. The connector body 10, in turn, restrains thesynthetic or other rope 50 while under tension. This feature is bothunique and useful for offshore mooring systems composed of multiplesynthetic and other rope sections in deep water.

We claim:
 1. A detachable connector for a rope, comprising: a connectorbody with a left side and a right side configured to receive the ropewrapped around said connector body, a bale with an apex, a right side, aleft side, a bottom right side end and a bottom left side end mounted onand detachable from said connector body, a main load pin subassemblyextending from the right side to the left side of both the connectorbody and the bale, and a restraining load subassembly extending from theright side to the left side of the connector body, wherein the bale isrecessed into the connector body, the load pin subassembly withconnecting plates being recessed into the bale, wherein the bale has across section varied along its right side and its left side from itsbottom right side end and its bottom left side end to its apex, whereinthe connector body further comprises a cavity extending from the rightside to the left side of the connector body to receive said main loadpin subassembly, a hole extending from the right side to the left sideof the connector body to receive said restraining load subassembly, andrecesses on the right and left sides of the connector body torespectively receive and constrain the bottom right side end and thebottom left side end of the bale and the bale further comprises a holeextending from the right side of the bale to the left side of the baleto receive the main load pin subassembly, said hole having recesses onthe right side of the bale and the left side of the bale and wherein themain load pin subassembly comprises a main load pin with a right end anda left end, each of said ends having threaded holes, a shoulder on oneof said ends configured to seat in the right and left side recesses ofthe bale, a circular end plate on the other of said ends, configured toseat in one of the recesses of the bale.
 2. The detachable connector ofclaim 1 wherein the restraining load subassembly comprises a mainrestraining pin having a right end and a left end, each of said endsfitted with padeye caps and retaining pins.